The present invention relates to a buffer circuit employing field effect transistors, and more particularly to a buffer circuit of a boot-strap type.
Buffer circuits have been widely utilized in variety of digital ICs such as IC memories.
A typical conventional buffer employs a flip-flop circuit having a pair of output nodes and a pair of boot-strap circuits provided to the pair of output nodes. Each of the boot-strap circuit includes a capacitor for achieving the boot-strap function. However, in the conventional buffer circuit, the capacitors of both the boot-strap circuits are simultaneously precharged by an activation signal each time when the buffer circuit is about to produce new contents of output signals, although the boot-strap circuit coupled to the output terminal from which a low level signal is produced is not required to operate.
Therefore, unnecessary power is consumed by the above boot-strap circuit and the load of the activation signal is large because the activation signal is required to charge both of the capacitors, resulting in a low speed operation.